The ceremony will take place at Tokyo’s Nippon Budokan, a large hall that has hosted concerts and sporting events, and was used for the last state funeral of a former prime minister in 1967.
Government spokesman Hirokazu Matsuno said Abe’s record as Japan’s longest-serving prime minister, his “truly commendable” achievements and his ties to foreign leaders made a state funeral appropriate.
“We will also accept foreign dignitaries, and countries with whom we have diplomatic relations will be advised of the details,” he added.
Abe was shot dead during the election campaign on July 8 in the western city of Nara. His accused killer, Tetsuya Yamagamiis in custody and allegedly targeted Abe because he believed the former leader was linked to the Unification Church.
Yamagami’s mother reportedly made large donations to the church, which her son blamed for the family’s financial difficulties.
A small private funeral for Abe was held at a temple in Tokyo shortly after his death, with thousands of people gathering outside to lay flowers and pay their respects.
The September ceremony will be only the second state funeral for a former prime minister in post-war Japan, after that of Shigeru Yoshidawho led the country after World War II.
Matsuno said the event would be “non-denominational, simple and dark”, adding that costs were still under consideration.
The plan is facing some backlash, with opposition parties questioning the spending of public funds on an event for a political leader.
An activist group has asked a Tokyo court to issue an injunction ending the funeral, although the government has said it does not view the event as a political statement to the public.
Abe was Japan’s best-known politician, maintaining a prominent place in public life even after stepping down in 2020 for health reasons.
But he was also a divisive figure who faced cronyism allegations and was criticized for his staunch nationalist views.